Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Convert Pounds to KG instantly with an exact, accurate formula -- no sign-up, no ads blocking the result.
Pounds and KG both measure weight, just in different systems; this tool applies the exact 0.45359237 factor between them the instant you type. Weight (more precisely, mass) conversions come up constantly across cooking, shipping, fitness, and international trade, since the US customary system (ounces, pounds, stones) and the metric system (grams, kilograms) are both widely used, often for the exact same real-world item described two different ways. One pound is defined as exactly 0.45359237 kilograms, or 16 ounces. The kilogram is the SI base unit of mass, equal to about 2.20462 pounds.
Enter your value and confirm the "From Unit" dropdown is set to Pounds -- the result grid updates instantly, showing your value converted into every unit in this weight category at once (not just KG), so you can see multiple equivalent measurements without switching tools. There's no button to press and nothing is sent to a server, so it works the same on a phone with no signal as it does on a desktop.
KG = Pounds × 0.45359237
The pound is defined as exactly 0.45359237 kilograms by the same 1959 international agreement that fixed the inch -- this makes pound-to-kilogram conversions exact, and every other US customary weight unit (ounces, stones) derives from that same fixed pound definition.
| Pounds | KG |
|---|---|
| 1 | 0.45359237 |
| 5 | 2.26796185 |
| 10 | 4.5359237 |
| 50 | 22.6796185 |
| 100 | 45.359237 |
International shipping and customs paperwork that requires a specific weight unit. Recipe conversion between US customary and metric weight-based ingredient lists. Fitness and health tracking that mixes pounds and kilograms across different apps or regions. For related conversions, see Pounds to Stones and Ounces Converter and GSM to LBS Paper Weight Converter.
This calculator carries full precision internally and only rounds the final displayed result for readability -- if you need more or fewer decimal places than shown, the underlying value is still exact to the limits of floating-point arithmetic.
Multiply the Pounds value by 0.45359237 to get KG. This calculator does that automatically as you type, so you don't need to do the multiplication by hand.
Yes -- 1 Pounds equals 0.45359237 KG by definition, so the result is mathematically exact rather than a rounded estimate (the displayed value may be rounded for readability, but the underlying calculation isn't).
Yes -- change the "From Unit" dropdown above the input to switch direction. The same conversion engine handles every unit in this category, not just Pounds and KG.
Technically mass, though "weight" is the everyday term used for both -- Pounds and KG here measure the same physical mass regardless of gravity, unlike a physics-specific "weight" (a force) which would vary depending on where it's measured.
KG is one of the standard units for measuring weight -- see the Practical Uses section above for the specific contexts where it's most commonly encountered.
100 pounds equals 45.359237 kg, using the same 0.45359237 factor as the rest of this page.
The exact pounds-to-kilograms factor is 0.4535924 -- multiply to convert forward, or multiply by 2.204623 to convert kilograms back to pounds. For example, 12.5 pounds × 0.4535924 = 5.669905 kilograms, and 3.5 pounds × 0.4535924 = 1.587573 kilograms.
One pound is defined as exactly 0.45359237 kilograms, or 16 ounces. The kilogram is the SI base unit of mass, equal to about 2.20462 pounds.
| Pounds | Kilograms |
|---|---|
| 1 | 0.4535924 |
| 2 | 0.9071847 |
| 3 | 1.360777 |
| 5 | 2.267962 |
| 10 | 4.535924 |
| 15 | 6.803886 |
| 20 | 9.071847 |
| 25 | 11.33981 |
| 50 | 22.67962 |
| 75 | 34.01943 |
| 100 | 45.35924 |
| 250 | 113.3981 |
| 500 | 226.7962 |
| 1,000 | 453.5924 |
How many kilograms are in 1 pounds?
1 pounds equals 0.4535924 kilograms.
How many pounds are in 1 kilograms?
1 kilograms equals 2.204623 pounds.
What is 150 pounds in kilograms?
150 pounds equals 68.03886 kilograms, using the same 0.4535924 factor as the rest of this chart.
Is this conversion exact or approximate?
The 0.4535924 factor comes from a fixed, exact definitional constant, so the underlying math is exact; the numbers on this page are rounded to seven significant digits for readability, and the calculator above keeps the full-precision value.
Values are rounded to seven significant digits for display; the converter above uses the full-precision factor.
Reference: NIST Weights and Measures